According to CrunchBase, they were founded in 2006, and they only took $18k in YC seed money (1/06), and $100k in seed money from Paul Graham and Paul Buchheit

According to CrunchBase, they were founded in 2006, and they only took $18k in YC seed money (1/06), and $100k in seed money from Paul Graham and Paul Buchheit (4/06). Even if that $35 million was mostly stock, it would seem to be a good return.